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1.
In the present work, polyamide/CaSO4 nanocomposites were prepared via melt intercalation on twin-screw extruder. Different particle sizes (23, 15, 10 nm) of CaSO4 were synthesized by in situ deposition technique and its sizes and shape were confirmed on a transmission electron microscope (TEM). The TEM study showed that nano-CaSO4 has a needlelike or fiberlike structure. Nano-CaSO4 was added from 1 to 4 wt% in the polyamide. Properties such as Tensile strength, Elongation at Break, Young's Modulus, and hardness were studied. These results were then compared with commercial CaSO4-filled polyamide composites. There was a propounding effect to be observed on properties of polyamide nanocomposites due to uniform dispersion of nano-CaSO4 and commercial CaSO4. The 4 wt% of 10 nm CaSO4 shows 16% improvement in Tensile Strength compared to commercial CaSO4 (11%) filled in polyamide composites, whereas, Elongation at Break decreases drastically in 10 nm CaSO4-filled polyamide nanocomposites up to 22% compared to commercial CaSO4-filled polyamide composites at 4 wt% loading (11%). Among these properties, Young's Modulus was found to be more effective in 4 wt% loading of 10 nm CaSO4 and was recorded to be 66% more compared to commercial CaSO4-filled-in polyamide composites (22%). Moreover, thermal properties such as thermal degradation and flammability were studied by TGA and flame testers. It was found that nano-CaSO4 was thermally more stable compared to commercial CaSO4-filled polyamide composites. Extent of dispersion of nano-CaSO4 was studied along with micro cracks generated during tensile testing using an Atomic Force Microscope (AFM).  相似文献   

2.
An in situ deposition approach was used for the synthesis of nano‐CaSO4 and nano‐Ca3(PO4)2. The nanosize particles were confirmed with an X‐ray diffraction technique. Composites of polypropylene (PP) with 0.1–0.5 wt % nano‐ or commercial CaSO4 or nano‐Ca3(PO4)2 were prepared. The transition from the α phase to the β phase was observed for 0.1–0.3 wt % nano‐CaSO4/PP and nano‐Ca3(PO4)2/PP composites. This was confirmed by Fourier transform infrared. A differential scanning calorimetry analysis was carried out to determine the thermal behavior of the nanocomposites with increasing amounts of the nano‐CaSO4 and nano‐Ca3(PO4)2 fillers. Increases in the tensile strength and Young's modulus were observed up to certain loading and were followed by a decrease in the tensile strength. A continuous decrease in the elongation at break (%) was also observed for commercial CaSO4 and larger nano‐Ca3(PO4)2. A decrease in the mechanical properties after a certain loading might have been due to the agglomeration and phase transition of PP in the composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 670–680, 2007  相似文献   

3.
Poly(vinyl chloride) (PVC) composites filled with nano‐ and micro‐CaCO3 particles were prepared via a melt blending method. Transmission electron microscopy images revealed better dispersion of nano‐CaCO3 than micro‐CaCO3 in the PVC matrix. With more than 5 phr (parts per 100 parts of resin) of nano‐CaCO3 content, both impact strength and heat stability were improved. Accelerated weathering tests were performed to investigate UV stability. The impact strength and white index obtained upon weathering exposure of PVC/(80 μm CaCO3) nanocomposites showed a significant improvement upon incorporating nano‐CaCO3. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers  相似文献   

4.
Poly(vinyl chloride) (PVC) nanocomposites with different contents of copper alumina (Cu-Al2O3) nanoparticles were prepared by the solution casting method. The effects of the nanoparticles on structural, thermal, electrical, contact angle and mechanical properties were thoroughly examined. The presence of Cu-Al2O3 in the macromolecular chain was confirmed through Fourier transform infrared (FTIR) spectroscopy. The X-ray diffraction (XRD) analysis of PVC nanocomposites showed the systematic arrangement of Cu-Al2O3 nanoparticles within the polymer, which indicated the higher crystallinity of the nanocomposites. The surface morphology of PVC was changed into hemispherical shaped particles by the inclusion of nanofiller was analyzed from SEM images. The glass transition temperature of the nanocomposites obtained from differential scanning calorimetry (DSC) was found to be increased with an increase in loading of nanoparticles in the polymer. The AC conductivity and dielectric studies revealed that the inclusion of nanofiller increases the electrical properties of the material and the composite with 7 wt.% sample showed the maximum conductivity and dielectric constant. The mechanical properties such as modulus, tensile strength, hardness, and impact properties of the PVC nanocomposites were significantly enhanced by the reinforcement of nanoparticles into the PVC matrix. The reinforcing mechanism behind the increase in tensile strength with the addition of nanoparticles was correlated with different theoretical models. The highest mechanical and electrical properties were observed for 7 wt.% Cu-Al2O3 loaded nanocomposite. Contact angle measurements of PVC with various loadings of Cu-Al2O3 nanofillers demonstrated that the nanoparticle attachment increased the hydrophobicity of the polymer matrix.  相似文献   

5.
A Brabender torque rheometer equipped with an internal mixer was used to study the influence of compounding method on the properties of (rigid PVC)/(treated and untreated nano‐CaCO3) nanocomposites. Two different methods were studied for the addition of surface treated and untreated nano‐CaCO3 during the melt mixing of rigid PVC. Direct dry mixing of rigid PVC and nano‐CaCO3, and addition of nano‐CaCO3 at the onset of PVC fusion were investigated. Dispersion of treated and untreated nano‐CaCO3 was studied by X‐ray diffraction and scanning electron microscopy. Results showed that using direct dry mixing improved the dispersion of nano‐CaCO3 in the PVC matrix by lowering the fusion time. The mechanical properties of the nanocomposite samples such as impact strength, tensile strength, and elongation at break were improved by using this method. The addition of treated nano‐CaCO3 at the onset of fusion caused a simultaneous decrease in torque. Also, rigid PVC nanocomposites prepared with treated nano‐CaCO3 showed better mechanical properties than those of nanocomposites prepared with the untreated nano‐CaCO3. J. VINYL ADDIT. TECHNOL., 18:153–160, 2012. © 2012 Society of Plastics Engineers  相似文献   

6.
The effects of particle size and surface treatment of CaCO3 particles on the microstructure and mechanical properties of poly(vinyl chloride) (PVC) composites filled with CaCO3 particles via a melt blending method were studied by SEM, an AG‐2000 universal material testing machine and an XJU‐2.75 Izod impact strength machine. The tensile and impact strengths of CaCO3/PVC greatly increased with decreasing CaCO3 particle size, which was attributed to increased interfacial contact area and enhanced interfacial adhesion between CaCO3 particles and PVC matrix. Titanate‐treated nano‐CaCO3/PVC composites had superior tensile and impact strengths to untreated or sodium‐stearate‐treated CaCO3/PVC composites. The impact strength of titanate‐treated nano‐CaCO3/PVC composites was 26.3 ± 1.1 kJ m−2, more than three times that of pure PVC materials. The interfacial adhesion between CaCO3 particles and PVC matrix was characterized by the interfacial interaction parameter B and the debonding angle θ, both of which were calculated from the tensile strength of CaCO3/PVC composites. Copyright © 2005 Society of Chemical Industry  相似文献   

7.
To improve the mechanical properties and structure of poly(vinyl chloride) (PVC)/nano‐CaCO3 nano composite, a core (nano‐CaCO3)/shell (SR) structured filler (40–60 nm) was successfully prepared by refluxing methyl vinyl silicone rubber (SR) and nano‐CaCO3 particles (coupling agent KH550, KH560, or NDZ‐101 as interfacial modifier) in toluene with vigorous stirring, according to an encapsulation model. It is effective in rigid PVC composite's toughness and reinforcement. The interfacial modifier's structure and interaction of nanocomposites of PVC/SR/nano‐CaCO3 were studied. The results indicate that KH560 has the optimal interfacial modificatory effect. The environmental scanning electron microscope (ESEM) study testified that PVC/SR/nano‐CaCO3 nanocomposites had a typical rubber–plastics‐toughening mechanism. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2560–2567, 2006  相似文献   

8.
Polyamide-CaCO3 nanocomposites were prepared by melt intercalation on twin-screw extruder. Various particle sizes (23, 17 and 11 nm) of CaCO3 were synthesized by in-situ deposition technique. The shape and sizes of nano-CaCO3 particles were confirmed by transmission electron microscopy (TEM). Nano-CaCO3 was added from 1 to 4 wt% in the polyamide. Properties such as Tensile strength, Elongation at break, Hardness, and Flame retardency were studied. These results were compared with commercial CaCO3 filled composites. Nano-CaCO3 filled in polyamide shows, 3 fold improvement in Young's modulus in comparison to commercial CaCO3 and 4–7 folds to virgin polyamide. Besides that, a polyamide nanocomposite shows 2 times improvements in flame retarding and vicat softening properties compared to commercial CaCO3. Moreover, thermal degradation was studied on TGA and found to be improved compared to commercial CaCO3. This was due to uniform dispersion of nano-CaCO3 with greater surface area in comparison to commercial CaCO3 in the polyamide matrix. Extent of dispersion of nano-CaCO3 was studied along with microcracks generated during tensile testing using scanning electron microscope (SEM).  相似文献   

9.
孙水升  张玲  李春忠  曹宏明  周秋玲 《化工学报》2005,56(11):2233-2239
选择了不同的表面处理剂对纳米CaCO3进行表面改性. 研究了不同表面处理剂对CaCO3/PVC纳米复合材料微观结构、界面结合强度、力学性能及加工性能的影响.研究表明,钛酸酯偶联剂处理可使纳米CaCO3颗粒在PVC基体中达到良好分散,明显改善纳米CaCO3颗粒与PVC基体之间的界面结合,并提高其界面结合强度.力学性能和流变性能研究表明,钛酸酯处理的纳米CaCO3填充PVC具有更高的拉伸强度、冲击强度以及更低的平衡转矩, 而且CaCO3/PVC复合材料的冲击韧性在填充量为20%(mass)时达到最大值26.5 kJ•m-2,是纯PVC的4倍.  相似文献   

10.
In the present work, polyamide-Mg(OH)2 nanocomposites were prepared via melt intercalation on a twin-screw extruder. Different particle sizes (24, 20, 11 nm) of Mg(OH)2 were synthesized by in-situ deposition technique and its shape and sizes was confirmed on transmission electron microscope (TEM). Nano-Mg(OH)2 was added from 1 to 4 wt% in the polyamide. Properties such as tensile strength, elongation at break, hardness, and flame retardency were studied. These results were then compared with commercial Mg(OH)2-filled composites. There was propounding effect to be observed on properties of polyamide nanocomposites due to uniform dispersion of nano-Mg(OH)2 and commercial Mg(OH)2. Moreover, thermal property like thermal degradation was studied on TGA. Extent of dispersion of nano-Mg(OH)2 was studied along with microcracks generated during tensile testing using AFM. It was found that nano-Mg(OH)2 is thermally more stable compared to that of commercial Mg(OH)2. Besides that, Tg and M.T. are studied on DSC.  相似文献   

11.
Silicon nitride based nanocomposites have been prepared with different amount (1 and 3 wt%) of multilayer graphene (MLG) as well as exfoliated graphite nanoplatelets (xGnP) and nano graphene platelets (Angstron) in comparison. The microstructure and mechanical properties of the graphene reinforced silicon nitride based composite materials have been investigated. Homogeneous distribution of the MLG additives have been observed on the fracture surface of the sintered material. The scanning electron microscopy examinations showed that graphene platelets are inducing porosity in matrix. The bending strength and elastic modulus of MLG/Si3N4 composites showed enhanced values compared to the other graphene added silicon nitride ceramic composites. These observations may be explained by the different type and quality of the starting materials and by the dispersion grade of graphene platelets having direct impact to the resulting density of the sintered samples.  相似文献   

12.
The mechanical and viscoelastic properties of an epoxy-polyamide coating containing nano and micro sized ZnO particles were studied. The nanocomposites were prepared at different loadings of the nano sized ZnO particles. The composites were also prepared using micro sized ZnO particles at different lambdas (lambda (λ) = PVC/CPVC). The optical properties of each nanocomposite were studied by UV–vis technique. Dynamic mechanical thermal analysis (DMTA) and micro-Vickers were used to investigate the mechanical properties of the composites. The viscoelastic properties of the composites were studied by a tensile test. The fracture morphologies of the composites were studied by a scanning electron microscope (SEM). An increase in Tg together with a decrease in cross-linking density of the composites was obtained when the coating was reinforced with the micro sized ZnO particles. On the other hand, the Tg and cross-linking density of the composites were decreased using nano sized ZnO particles. It was also found that, the Young's modulus and the fracture energy of the coating were decreased using micro and nano sized ZnO particles. The greater toughness as well as fracture energy of the composite was obtained when it was reinforced with the nano sized ZnO particles. The curing behavior of the epoxy coating was affected in the presence of the micro and nano sized ZnO particles.  相似文献   

13.
Nanocomposites of poly(vinyl chloride) (PVC) and nano‐calcium carbonate (CaCO3) particles were prepared via melt blending, and chlorinated polyethylene (CPE) as an interfacial modifier was also introduced into the nanocomposites through preparing CPE/nano‐CaCO3 master batch. The mechanical properties, morphology, and rheology were studied. A moderate toughening effect was observed for PVC/nano‐CaCO3 binary nanocomposites. The elongation at break and Young's modulus also increased with increasing the nano‐CaCO3 concentration. Transmission electron microscopy (TEM) study demonstrated that the nano‐CaCO3 particles were dispersed in a PVC matrix uniformly, and a few nanoparticles agglomeration was found. The toughening effect of the nano‐CaCO3 particles on PVC could be attributed to the cavitation of the matrix, which consumed tremendous fracture energy. The notched Izod impact strength achieved a significant improvement by incorporating CPE into the nanocomposites, and obtained the high value of 745 J/m. Morphology investigation indicated that the nano‐CaCO3 particles in the PVC matrix was encapsulated with a CPE layer through preparing the CPE/nano‐CaCO3 master batch. The evaluation of rheological properties revealed that the introduction of nano‐CaCO3 particles into PVC resulted in a remarkable increase in the melt viscosity. However, the viscosity decreased with addition of CPE, especially at high shear rates; thus, the processability of the ternary nanocomposites was improved. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2714–2723, 2004  相似文献   

14.
The incorporation of fillers into elastomers has profound effects on the mechanical, physical, and thermal properties of the nanocomposites that form. In this study, styrene–butadiene rubber as a matrix was reinforced separately with 10‐, 15‐, or 23‐nm CaSO4, which was synthesized by an in situ deposition technique. The mixing and compounding were performed on a two‐roll mill, and sheets were prepared in a compression‐molding machine. Properties such as the swelling index, specific gravity, tensile strength, elongation at break, modulus at 300% elongation, Young's modulus, hardness, and abrasion resistance were measured. The morphology of the rubber nanocomposites was also performed with scanning electron microscopy to study the dispersion of the nanofiller in the rubber matrix. The thermal decomposition of the rubber nanocomposites was studied with thermogravimetric analysis, and the results were compared with those of commercial CaSO4‐filled styrene–butadiene rubber. A reduction in the nanosizes of CaSO4 led to an enhancement of the mechanical, physical, and thermal properties of the rubber nanocomposites. Above a 10 wt % filler loading, the styrene–butadiene rubber showed a reduction in all properties. This effect was observed because of the agglomeration of the nanoparticles in the rubber matrix. The thermodynamic parameters were also studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2018–2026, 2007  相似文献   

15.
CaCO3/acrylonitrile‐butadiene‐styrene (ABS) and CaCO3/ethylene‐vinyl acetate copolymer (EVA)/ABS nanocomposites were prepared by melting‐blend with a single‐screw extruder. Mechanical properties of the nanocomposites and the dispersion state of CaCO3 particles in ABS matrix were investigated. The results showed that in CaCO3/EVA/ABS nanocomposites, CaCO3 nanoparticles could increase flexural modulus of the composites and maintain or increase their impact strength for a certain nano‐CaCO3 loading range. The tensile strength of the nanocomposites, however, was appreciably decreased by adding CaCO3 nanoparticles. The microstructure of neat ABS, CaCO3/ABS nanocomposites, and CaCO3/EVA/ABS nanocomposites was observed by scanning electron microscopy. It can be found that CaCO3 nanoparticles were well‐dispersed in ABS matrix at nanoscale. The morphology of the fracture surfaces of the nanocomposites revealed that when CaCO3/EVA/ABS nanocomposites were exposed to external force, nano‐CaCO3 particles initiated and terminated crazing (silver streak), which can absorb more impact energy than neat ABS. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

16.
Poly(vinyl chloride) (PVC)/organophilic‐montmorillonite (OMMT) nanocomposites were prepared by direct melt intercalation. PVC/compatibilizer ((vinyl acetate) copolymer (VAc))/OMMT nanocomposites were also prepared by melt intercalation by a masterbatch process. The effect of OMMT content on the nanostructures and properties of nanocomposites was studied. The nanostructures were studied by wide angle X‐ray diffraction (WAXD) and transmission electron microscopy (TEM). The linear viscoelastic properties and dynamic mechanical properties of PVC/OMMT nanocomposites were also investigated by an advanced rheometric expansion system (ARES) rheometer. The results showed that partially exfoliated and partially intercalated structures coexisted in the PVC/OMMT and PVC/VAc/OMMT nanocomposites. The mechanical properties test results indicated that the notched Charpy impact strengths of nanocomposites were improved compared to that of pristine PVC and had a maximum value at 1 phr OMMT loadings. The compatibilizer could further improve the impact strengths. But the existence of OMMT decreased the thermal stability of PVC/OMMT and PVC/VAc/OMMT nanocomposites. The linear viscoelastic properties test results indicated the dependence of G′ and G″ on ω shows nonterminal behaviors, and they had better processibility compared with pristine PVC. However, the glass transition temperatures of PVC/OMMT nanocomposites almost had little change compared to that of pristine PVC. POLYM. COMPOS., 27:55–64, 2006. © 2005 Society of Plastics Engineers  相似文献   

17.
Nanosilica particles are functionalized by in situ surface‐modification with trimethyl silane and vinyl silane. Resultant reactive nanosilica (coded as RNS) contains double bonds and possesses good compatibility with vinyl chloride (VC) and polyvinyl chloride (PVC). This makes it feasible for RNS to copolymerize with VC generating RNS/PVC composites via in situ suspension polymerization. As‐prepared RNS/PVC composite resins are analyzed by means of FTIR. The tensile strength and impact strength of compression‐molded RNS/PVC composites are measured and compared with that of compression‐molded PVC composites doped with dispersible nano‐SiO2 particles (abridged as DNS) surface‐modified with trimethyl silane alone. Moreover, the thermal stability of compression‐molded RNS/PVC and DNS/PVC composites is evaluated by thermogravimetric analysis. It has been found that RNS/PVC composites possess greatly increased impact strength and tensile strength than PVC matrix, while DNS/PVC composites possess higher impact strength than PVC matrix but almost the same tensile strength as the PVC matrix. This implies that DNS is less effective than RNS in improving the mechanical strength of PVC matrix. Particularly, RNS/PVC composites prepared by in situ suspension polymerization have much higher mechanical strength than RNS/PVC composites prepared by melt‐blending, even when their nanosilica content is only 1/10 of that of the melt‐blended ones. Besides, in situ polymerized RNS/PVC and DNS/PVC composites have better thermal stability than melt‐blended nanosilica/PVC composites. Hopefully, this strategy, may be extended to fabricating various novel high‐performance polymer‐matrix composites doped with organically functionalized nanoparticles like RNS. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

18.
A new method of surface chemical modification of nano‐SiO2 was proposed in the paper. In the presence of catalyst, the active hydroxyl groups on the surface of nano‐SiO2 reacted with AB2‐type monomer (N,N‐dihydroxyethyl‐3‐amino methyl propionate) by one‐step polycondensation. And the product's Fourier transform infrared graphs and transmission electron microscopy (TEM) images proved that hyperbranched poly(amine‐ester) (HPAE) was grafted from nano‐SiO2 surface successfully. Moreover, polyvinyl chloride (PVC)/modified nano‐SiO2 composites were made by melt‐blending. The composites' structures and mechanical properties were characterized by TEM, scanning electron microscopy, and electronic universal testing machine. The results showed that nano‐SiO2 grafted by HPAE increased obviously in dispersion in PVC matrix, and mechanical properties of PVC were effectively improved. Additionally, it was found that mechanical properties of PVC/nano‐SiO2 composites reached the best when weight percent of nano‐SiO2 in PVC matrix was 1%. Compared with crude PVC, the tensile strength of HPAE grafted nano‐SiO2/PVC composite increased by 24.68% and its break elongation, flexural strength, and impact strength increased by 15.73, 4.07, and 184.84%, respectively. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers  相似文献   

19.
ABSTRACT

Conjugated polymer/graphite nanocomposites have been known as high performance materials owing to improve the physicochemical properties relative to conventional once. Multilayered polymer nanocomposites based on polypyrrole (PPy), polyvinylchloride (PVC) as matrices and p-phenylene diamine (PDA) as linker were prepared via chemical in situ polymerization process and subsequently investigated the physical characteristics of fabricated nanocomposites at various loadings. The structural characterization and morphology of prepared nanocomposites were inspected by Fourier transform infrared spectroscopy (FTIR), X-ray photon spectroscopy (XPS), energy dispersive X-ray spectroscope (EDX), field emission scanning electron microscope (FESEM), respectively. The composite III showed higher thermal stability at 10 wt% loading of PPy. According to differential scanning calorimetry (DSC), the glass transition temperature (Tg), melting temperature Tm, and crystallization temperature (Tc) of nanocomposites increases with PPy loading (2–10 wt%) owing to crosslinking and chain rigidity. Moreover, higher surface area was displayed by the multilayered PPy/PVC/PDA@FG nanocomposites. Remarkably, electrical conductivity of ultimate nanocomposites was also found to be a function of PPy loading.  相似文献   

20.
Poly(vinyl chloride) (PVC) is one of the major thermoplastics and many scientific and technological efforts have been performed by the incorporation of different additives. The main purpose of this work is the design, fabrication, and experimentally characterization of PVC ternary composites. Acrylonitrile‐butadiene‐styrene (ABS) core‐shell rubber particles and nano‐CaCO3 particles were employed to modify hard PVC simultaneously. Transmission electron microscopy (TEM), scanning electron microscope (SEM), and mechanical test were used to evaluate the properties of the composites. Mathematical models for the mechanical properties of PVC ternary composites were investigated by using a method combining design of experiments (DOE), Kriging surrogate model, and data analysis to investigate the various weight ratios addition of nano‐CaCO3 and ABS on the mechanical properties of compounded PVC and predict mechanical properties associated to the studied composites. Benefiting from the proposed strategy, more reliable results and accurate predictions of mechanical properties of the nanocomposites can be extracted from Kriging surrogate model. POLYM. ENG. SCI., 56:1109–1117, 2016. © 2016 Society of Plastics Engineers  相似文献   

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